CSS规则visibility:hidden和display:none都会导致元素不可见。这些是同义词吗?
当前回答
总结所有其他答案:
| visibility | display |
|---|---|
| element with visibility: hidden, is hidden for all practical purposes (mouse pointers, keyboard focus, screenreaders), but still occupies space in the rendered markup | element with display:none, is hidden for all practical purposes (mouse pointers, keyboard focus, screenreaders), and DOES NOT occupy space in the rendered markup |
| css transitions can be applied for visibility changes | css transitions can not be applied on display changes |
| you can make a parent visibility:hidden but a child with visibility: visible would still be shown | when parent is display:none, children can't override and make themselves visible |
| part of the DOM tree (so you can still target it with DOM queries) | part of the DOM tree (so you can still target it with DOM queries) |
| part of the render tree | NOT part of the render tree |
| any reflow / layout in the parent element or child elements, would possibly trigger a reflow in these elements as well, as they are part of the render tree. | any reflow / layout in the parent element, would not impact these elements, as these are not part of the render tree |
| toggling between visibility: hidden and visible, would possibly not trigger a reflow / layout. (According to this comment it does: What is the difference between visibility:hidden and display:none? and possibly according to this as well https://developers.google.com/speed/docs/insights/browser-reflow) | toggling between display:none to display: (something else), would lead to a layout /reflow as this element would now become part of the render tree |
| you can measure the element through DOM methods | you can not measure the element or its descendants using DOM methods |
| If you have a huge number of elements using visibility: none on the page, the browser might hang while rendering, as all these elements require layout, even though they are not shown | If you have a huge number of elements using display:none, they wouldn't impact the rendering as they are not part of the render tree |
资源:
https://developers.google.com/speed/docs/insights/browser-reflow http://www.stubbornella.org/content/2009/03/27/reflows-repaints-css-performance-making-your-javascript-slow/ visibility:hidden和display:none
其他信息:
还有一些浏览器支持特性，但它们似乎适用于非常老的浏览器，在其他答案中也有，所以我在这里没有讨论它们。 还有其他一些隐藏元素的方法，比如不透明度，或者屏幕外的绝对定位。所有这些方法在一些或其他的回答中都有涉及，并且都有一些缺点。 根据这条评论(可见性:hidden和display:none之间的性能差异)，如果你有很多元素使用display:none并且你将其更改为display:(其他)，它将导致单个回流，而如果你有多个可见性:hidden元素并且你将它们变为可见，它将导致每个元素的回流。(我不太明白)
其他回答
display: none;
它将不会出现在页面上，也不会占用任何空间。
visibility: hidden;
它隐藏了一个元素，但它仍然会占用与之前相同的空间。元素将被隐藏，但仍然会影响布局。
可见性:隐藏保留空间，而显示:无不保留空间。
无示例:https://www.w3schools.com/css/tryit.asp?filename=trycss_display_none
示例:https://www.w3schools.com/cssref/tryit.asp?filename=trycss_visibility
有一件事值得补充，尽管它没有被问到，是有第三个选项，使对象完全透明。考虑:
1 <a href="http://example.com" style="display: none;"> < / >链接。< br / > <a href="http://example.com" style="可见性:隐藏;"> < / >链接。< br / > <a href="http://example.com" style="不透明度:0;"> < / >链接。
(请务必点击上面的“运行代码片段”按钮查看结果。)
1和2之间的区别已经指出了(即2仍然占据空间)。但是，2和3之间有区别:在情况3中，鼠标停留在链接上时仍然会切换到手，用户仍然可以单击链接，Javascript事件仍然会在链接上触发。这通常不是你想要的行为(但有时可能是?)
另一个区别是，如果你选择文本，然后复制/粘贴为纯文本，你会得到以下结果:
1st link.
2nd link.
3rd unseen link.
在情况3中，文本被复制了。也许这对于某种类型的水印是有用的，或者如果你想隐藏一个版权声明，如果一个粗心的用户复制/粘贴你的内容会显示出来?
Display: none将元素从页面中完全移除，并且构建页面时就好像该元素根本不存在一样。
可见性:隐藏保留文档流中的空间，即使您再也看不到它。
这取决于你在做什么，可能有也可能没有很大的区别。
Display:none表示所讨论的标签根本不会出现在页面上(尽管您仍然可以通过dom与它进行交互)。在其他标记之间不会为它分配空间。
可见性:隐藏意味着与display:none不同，标签是不可见的，但是在页面上为它分配了空间。标签被渲染，只是在页面上看不到。
例如:
test | <span style="[style-tag-value]">Appropriate style in this tag</span> | test
将[style-tag-value]替换为display:none会导致:
test | | test
用可见性替换[style-tag-value]:隐藏结果:
test | | test
另一个区别是可见性:hidden在非常非常老的浏览器中有效，而display:none则不行:
https://www.w3schools.com/cssref/pr_class_visibility.asp
https://www.w3schools.com/cssref/pr_class_display.asp
